The present invention is related to agricultural apparatus using substantially horizontal discs for cultivating, planting, or spreading chemicals.
The planting of seeds is usually accomplished commercially on farms through the use of elaborate seed drills. Such drills typically include a furrow opener and a seed discharge tube behind the furrow opener. Seed is dropped through the tube and into an open furrow formed in the ground surface. This furrow must then be closed over the top of the seeds, usually by trailing tamping wheels.
Cultivating the ground surface is not usually accomplished simultaneously with the planting operation. Cultivating also involves breaking of the ground surface by some type of ground opening and soil manipulating device pulled along behind a tractor. Examples are harrows, rod weeders, plows, etc.
Subsoil discs have been used that are pulled in a horizontal orientation below the soil surface for cultivating, planting and fertilizing. They may rotate below the ground surface as they are pulled in a forward direction to engage and cut through the roots of weeds and to slightly lift and agitate the soil above the disc. The advantage of horizontal disc cultivating is that the horizontal oriented discs require minimal pulling forces for movement through the soil. Another advantage is that the soil surface is not substantially disturbed.
After loosening the soil with a horizontally rotatable disc, a seeding operation may follow in which a furrow is opened and the seed is then planted in the previously cultivated soil. This not only involves a second operation but requires additional energy to open the planting furrow and close it again. Further, the disruption of the soil surface may encourage loss of top soil through erosion from wind and water.
Modern soil treatment includes the application of various forms of gaseous chemicals to the soil. Obviously, unless the gas is heavier than air there must be some provision for injecting and maintaining the gas in contact with the soil. Various subsurface tools have been devised for sub-surface injecting or releasing of gaseous chemicals. The injectors themselves may operate effectively but the ground engaging element leading to the discharge often presents a problem. Trash builup on the leading edge of the ground engaging elements forms furrows of increasing size as the implement is pulled along, especially in stubble for "no till" operations. The enlarged furrow leads down to the gas discharge and therefore provides an easy escape route for the gases.
Known forms of horizontal disc cultivators, planters, or fertilizer spreaders use rotating discs on fixed or pivoted upright shafts or tubes. None, however, have adequate bearing mounts for the discs, especially where the discs and attached shafts or tubes rotate with the discs. Forces applied to the discs and shafts, as well as the gritty environment have often caused early bearing failure or bending along the supporting shafts or tubes. The force and wear factors increase in "no till" applications where the cultivating, planting, etc. is to be accomplished in stubble. It is practically impossible to rotatably support a subsoil implement about an upright axis by bearings arranged as demonstrated by prior forms of such implements in no till operations.
It therefore becomes desirable to provide some effective form of sub-surface implement that will enable cultivating, planting or dispersion of fertilizer material with minimal disruption of the soil surface, along with adequate bearing support that will allow operation in "no till" situations.